Carburetor



y Feb. 7, 1933.

Original Filed Sept. 5, 1929 P. s. TICE CARBURETOB ZEW/622222 Um 01A 5514.7 ozyzeys A V2 sheets-sheet 1 Patented Feb. 7, 1933' UNITED e STA-TESPATENT oFFlucE PEBCIVAL S. TICE OF CHICAGO, ILLINOIS, .ABSIGNOR TSTEWABT-W'ABNEB CORPORA- TION, 0I' CHICAGO, ILLINOIS, A CORPORATION OFVIRGINIA.

Original application l'ed September 5,

This invention is a division of my nding application Serial No. 390,602,filed eptember 5, 1929. The purpose of the invention to be defined inthis application is to provide an improved type of carburetor havingmeans for varying the rate of fuel supply momentarily for pur- Y posesfor which momentary increase of fuel supply is needed. It consists inthe elements and features of construction shown and de'- scribed asindicated in the claims.

In the drawings;

Figure 1 is a top plan view of a carburetor embodying this inventionhaving fuel feeding pump mounted upon it and included in the view.

Figure 2 is a side elevation of the same.

'Figure 3 is a section at the line 3 3 on Figure 1.

Figure 4 is a section at the line 4-4 on Figures 2 and 3.

Figure 5 is a side elevation of the carburetor shown mounted on theengine with certain parts broken away to disclose interior parts.

Figure 6 lis a section at the line 6--6 on Figure 5.

Figure 7 is a section at the line 7-7 on Figure 5 showing a standpipearranged for being occupied by, fuel injected into it by means shown inFigures 4 and 5 to be fed by hydrostatic pressure to the fuel nozzleunder certain running conditions of the engine.

The carburetor construction shown in the drawings comprises a bodymember, A, having an air and fuel mixture conduit, 20, leading insubstantially horizontally from the air inlet, 21, at which the airenters, and conto the upper end of said body member at w ich 'the latteris adapted -for mounting at the engine intake for discharge into theintake manifold, a choke valve, 23, bein provided at the entrance andthe throttle va ve, 24, be` ing mounted at the upper discharge end.

In the ,upwardly extendin part of said conduit there is mounted ag'enturi sleeve, 26, having formed `integrally with it a nozzle member,27, hereinafter more particularly described. f

1929, Serial No. 390,802. Dividedand this application tiled October 25,1930. Serial 11o. 491,129.

The body member comprises also a fuel accumulating chamber, 30,extending adjacent theupwardly extending part ofthe air and lfuelmixture conduvi-tat the side opposite the air inlet and choke valve,said chamber extending down around and under the con- Yex side of the 90degree bend mentioned.

The fuel chamber extending to the lower end of the body member, A, isclosed at the bottom by a flexible diaphragm, 47, clamped in place by askeleton ca 45, with a damping plate, 48, above the iaphragm having acentral aperture. affording limited access of the fuel to the diaphragmfor operating hydrostatically thereon for controlling the opening andclosing of an electric switch represented by the contact-carryingmembers,

64 and 65, of the electric circuit in which is energized the electricpump comprised in the casing, B, and by which the fuel is fed tothecarburetor.

Referring to the part of the structure constituting the carburetorproper: The fuel discharge member, vcommonly called the nozzle, is inthe form of a lbridge piece, 200, extending diametrically across theVenturi passage at the throat of the latter, said bridge aving alongitudinal passage, 201, from which, intermediate the ends of thepassage, the bridge is apertured as seen at 202 for upward discharge ata transverse'notch, 203, across which there is protruded a short ductmember, 204, which constitutes the terminal of a duct, 205, parallelwith the passage, 201, said duct, 205, leading infrom the groove, 206,in the outer surface of the' Venturi sleeve element, said grooveextending for 90 around the sleeve for communicating with the passage,208 formed in the body, A, and leading to a discharge port, 208",situated immediately beyond theseating position of the throttle valve,24.

The purpose of this fuel flow course will be recognized as being tosupply fuel to the engine when the throttle is nearly closed as atidling position. For the purpose of momentarily accelerating thedischarge of fuel formed with what are hereinafter referred to asvariable capacity chambers.

For the pur chambers, the ody, A, is formed at opposite sides ofthe airand fuel mixture conduit with circular protruding bosses, 209 and 219,respectively, having circular recesses, 209*l and 219, respectively,which recesses become variable capacity chambers by being closed orcovered by flexible diaphragme, 210 and 220,

respectively, which are clamped at their margins between the marginalareas of the bosses, 209 and 219, respectively, by cover members, 211and 221, respectively, having their marginal flanges, 211 and 221, matedwith the marginal areas of the bosses for so clamping said diaphragm.

Access for fuel from the fuel chamber, 30, into the variable capacitychambers, 209a and 219, respectively, is afforded by ports, 214 and 224,controlled by check valves, 214a and 224, respectively, opening for flowfrom the fuel chamber into said variable capacity chambers and seatingagainst reverse flow.

Substantially at the vertical la-ne of the common axis of the twovariable capacity chambers, there are formed in the body member, A, atopposite sides of the air and fuel mixture conduit and inwardly from thevariable capacity chambers, respectively, vertically extending ducts,216 and 226, respectively, which open at their upper ends by transverseducts, 217 and 227, respectively, for registration with the oppositeends of the longitudinal passage, 201, of the nozzle bridge.

Flow communication from the variable capacity chambers to vthe ducts,216 and 226, respectively, is afforded by ports 218 and 228, formed inthe inner walls of said variable capacity' chambers, respectively, andopening at their inner ends in said ducts, 216 and 226. These ports aredesirably supplied with low-restrictmg fittings, 219 and 229,respectively. Y

'The purposes of these variable capacity chambers with their respectiveiexible diaphragm walls, are, as above stated, to afford momentaryacceleration of fuel flow desirable under certain conditions of engineoperation. F or this purpose in respect to the variable capacitychamber, 209, the diaphragm, 210, has secured to it at the center, astem, 210", by which also there are clamped upon opposite sides of thediaphragm rigid disks, 210, limiting its flexure to an annular areaoutside 'said disks, and there is provided a spring, 210, reacting onthe stem for flexing the diaphragm outwardly to give the chamber, 209,maximum capacity. For housing the spring, 210, and for guiding thediaphragm stem in its action, there is provided a sleeve,

210, for which the inner wall of the chamber, 209, is bored, the boreextending across the se of such variable capacity -avoiding trapping ofthe air at armena duct, 216, and the sleeve being inserted thereinblockading the duct at that point.

The inner end of the diaphragm stem, 210", dimensioned for slide it 'insaid sleeve, 210B, is bored at its inner end for seating and centeringthe spring, 210, whose opposite end is centered in a slight centralrecess, 210f, at the inner end of the bore which is occupied by thesleeve, 210.

The chamber, 209, being thus normally expanded to maximum capacity,andbeing normally filled with the fuel from the fuel chamber, it will beunderstood that upon the diaphragm being thrust inwardly for reducingthe capacity of the chamber,V the fuel will be forcibly discharged fromthe chamber by way of the restricted port in the fitting, 219', thusmomentarily and instantaneously increasing the fuel discharge, the checkvalve, 214, seating a ainst flow from the variable capacity chamer backto the fuel chamber, insuring that the chamberreducing movement of thediaphragm will thus eject the fuel toward the nozzle and not drive itback into the fuel chamber.

The diaphragm is operated for this fuel discharging movement by a lever,230, fulcrumed at 231 on a bracket arm, 211, which projects from theclosure member, l211, of the variable capacity chamber, 209, the lowerterminal, 230, of said (lever bearing against the protruding end of thediaphragm stem, 210D; and the other end of the lever which extendsupward and inwardly toward the throttle lever stem, terminates bearingagainst the hub of the throttle valve operatlever in the direction forthrusting the diaphragm, 210, inwardly as described, for reducing thecapacity of the chamber and eJecting the fuel therefrom, In order thatthe variable capacity chamber may fill completely with the liquid, theupper part, there is provided a restricted vent port, 209m, opening inthe fuel chamber, 30. This vent port is utilized for effecting a limitedgoverning of the momentarily increased fuel discharge which is caused bythe chamberreducing movement of the diaphragm, rendering that dischargeless forcible when the fuel is relatively hot,-.as when the engine hasbeen running and become heated, causing the carburetor to be somewhatheated,- so that it flows more freely under a given impulse thanwhen'the fuel is cold as at startspring, 209, secured at one end to thefixed wall of the variable capacity chamber, and having the free endlapping valve-wise on the vent port; the two metals of which the stripis composed being related as to rate ofexpansion by increase oftemperature, so that when cold, the valve end of the stri is seated atand closes thevent port; and w en the temperature rises to apredetermined degree the flexure of the bi-metallic strip withdraws thevalve end from the port correspondingl to the rise of temperature whicht e strip erives mainly from the fuel which occupies the chamber.

The variable vent which is thus effected for the fuel, ermitting itsflow back into the fuel cham r under the impulse of thecapacity-reducing movement of the diaphragm, causes variation inversely,but to a corresponding degree, o f the amount of fuel which the impulsewill discharge to the duct leading to the nozzle.

This feature consisting of the temperaturecontrolled vent for -the fuelunder theimpulse derive-d from the opening of the throttle, is fullyshown in my Patent No. 1,7 7 6,988, issued September 30, 1930, in whichthe vent port opens directly into the fuel chamber. In the presentconstruction .there is provided a stand pipe, 245, projecting up in thefuel chamber nearly to the top thereof, with a vent port, 209m, leadinginto the lower end of said stand pipe so that the fuel dischargedthrough the vent port under the chamber-'reducing impulse of thediaphragm, 210, is segregated from the. total fue supply in the fuelchamber, 30, (and may-overflow into said chamber), so that it operatesfor" prolonging-the extra temporary fuel dis-l charge from the nozzlewhich is caused by the momentary impulse of the diaphragm, whichotherwise would be only instantaneous and of unappreciable duration, aswill be obvious upon considering that the discharge would cease when themomentary impulse ceased, unless during that impulse fuel is moved to aposition from which it will continue to flow for discharge at the nozzleby pressure other than that momentarily exerted by the diaphra m.

t For it will be un erstood that, the vent serves to reduce the forceand velocity 0f the fuel discharge caused by the momentary impulse ofthe diaphragm,`without .reducing A the quantity but on the contraryincreasing the quantity by the amount discharged through the vent portand free to be returned under hydrostatic pressure due to the height ofthe 'standpipe to the variable capacity -chamber, andy by thathydrostatic pressure caused to maintain the How through the restrictedport in the fittin 219, tothe nozzle,

-thus prolonging the disc arge in compensation for the reduction ofvelocity, such prolongation or spreading of the extra fuel discharge andconsequent enrichment of fuel above the governed level mixture overseveral engine cycles, .being es eclally, deslrable for properlacceleration w en the engine is hot and thefuel in the amber isconsiderably heated.

ing means for free one-way flow through the variable capacity chamberfrom the accumulating chamber to the mixing chamber; a port arranged forrestricting'the fuel How in both directions between the fuelaccumulating chamber and the variable capacity chamber; means formomentarily operating the movable wall member for reducing the capacityof the variable capacity chamber for momentary acceleration of fuel flowfrom said chamber to the -mixing chamber, and a stand ipe in the fuelaccumulating chamber exten ing therein above the governed level thereof,said restricted port opening from the .variable capacity chamber intothe lower part of said stand pipe.

2. In a carburetor comprising afuel accumulating chamber and means forgovern-v ing the level to which the fuel may accumulate therein, anairand fuel mixing chamber and conduits therefrom leading for discharge atthe engine intake; fuel Aflow connection from the accumulating chamberto the mix- Ving chamber comprising a variable-capacity chamber having amovable wall member by whose movement the chamber capacity is varied;means for free one-way flow through the variable-capacity chamber fromthe accumulating chamber to the mixin chamber; a restricted port in thewall of t e variable capacity chamber formed for flow throughv it inboth directions, and a stand pipe open to atmospheric pressure intowhose lower end said restricted port leads.

3. In a carburetor comprising a fuel accumulating chamber and'means forgoverning the level to which the fuel may accumulate therein, and an airand fuel mixing chamber with conduits therefrom leading for' dischargeat the engine intake, fuel owconnection from the accumulating chamber tothe mixing chamber comprising an auxiliary chamber having free flowcommunication with the remainder of the fuel connection to the mixingchamber, and oneway flow communication for fuel How from the fuelaccumulating chamber; a standv pipe extending of the fuel accu'-mulating chamber and open to atmospheric peressure above said level, theauxiliary chamr having restricted fuel communication with said standpipe at the lower part thereof, and means for producing momentaryincrease of pressure in said auxiliary chamber for accelerating the fuelilow toward the mixing chamber.

4. In a carburetor comprising a fuel accumulating chamber and means forgoverning the level to which the fuel may accumulate therein, and an airand fuel mixing chamber with conduits therefrom leading for discharge atthe engine intake, fuel flow connection from the accumulating chamber tothe mixing chamber comprising an. auxiliary chamben having free flowcommunication with the remainder of the fuel connection tov the mixingchamber, and one-way flow communication for fuel flow from the fuelaccumulating chamber; a stand pipe extending in the fuel accumulatingchamber and open to thc fluid pressure therein above the governed levelof said chamber and havin a spillway to a point within the fuel supply,t e auxiliary chamber having restricted fuel communication with saidstand pipe at the lower part of the latter, and means for producingmomen tary increase of pressure in said auxiliary chamber for momentaryacceleration of the fuel flow toward the mixing chamber.`

5.A In a carburetor comprising a fuel accumulating chamber and means forgoverning the level to VWhich the fuel may accumulate therein, an airand fuel mixing chamber and a conduit therefrom leading for discharge atthe engine intake; a fuel flow connection from the accumulating chamberto the mixing chamber comprising a variable-capacity chamber having amovable wall member by whose movement the chamber capacity is varied:means for a one-wavl flow through the vaablecapacity chamber from theaccumulating chamber to the mixing chamber; a restricted port in thewall of the variablecapacity chamber formed for flow through it in bothdirections, and a stand pipe into which said restricted port leads. A Intestimony whereof, I have hereunto set my hand at Chicago, Illinois,this 22nd day of October, 1930.

PERCIVAL S. TICE.

